The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1, a functional block diagram of an engine system 100 is presented. The engine system 100 includes an engine 102 that produces drive torque. Air is drawn into the engine 102 through an intake manifold 104. A throttle valve 106 varies the volume of air drawn into the intake manifold 104. The throttle valve 106 is actuated by an electronic throttle controller (ETC) 108, thereby controlling opening of the throttle valve 106. The air mixes with fuel provided by a fuel injector 110 to form an air and fuel mixture.
The air/fuel mixture is combusted within one or more cylinders of the engine 102, such as cylinder 112. In various engine systems, such as the engine system 100, combustion of the air/fuel mixture is initiated by spark provided by a spark plug 114. Exhaust gas resulting from combustion is expelled from the cylinders to an exhaust system 116. The engine 102 transfers torque to a transmission 118 via a torque converter 120. The transmission 118 may then transfer torque to one or more wheels of the vehicle.
An intake valve and an exhaust valve are associated with each cylinder of the engine 102. For example, intake valve 122 and exhaust valve 124 are associated with the cylinder 112. Generally, opening of the intake and exhaust valves 122 and 124 is regulated based on rotation of a camshaft (not shown). However, the opening of the intake valve 122 and the exhaust valve 124 may be adjusted by an intake cam phaser 126 and an exhaust cam phaser 128, respectively.
An engine control module (ECM) 150 regulates torque output by the engine 102. The ECM 150 may regulate torque output of the engine 102 to, for example, meet torque demanded by a driver of the vehicle. The driver's torque demands are transmitted to the ECM 150 by a driver input module 132. In some circumstances, combustion within all of the cylinders of the engine 102 may not be necessary to meet the torque demands. Accordingly, the ECM 150 may instruct a cylinder deactivation module 130 to deactivate one or more of the cylinders of the engine 102. The ECM 150 may be said to be operating in an active fuel management (AFM) mode during the time that the cylinders are deactivated.